In general. the severe wind of an intense tropical cyclone (hurricane or typhoon). The term has no further technical connotation, but, unfortunately, is easily conftlsed with the strictly defined hurricane-force wind,

Rain gauge which registers precipitation that is too light to be registered by ordinary recording of the depth of water from precipitation. Same as ombrometer.

Federal Aviation Administration.

A strong wind characterized by a sudden onset, a duration on the order of minutes, and a rather sudden decrease in speed.

The direction, with respect to magnetic north, from which the wind is blowing. Distinguish from true wind direction.

A relatively small-scale, upward moving current of air.

An instrument used for measuring geometric angles. See radio direction-finder.

Defect in the action of an aneroid barometer resulting in a sluggish adjustment of the index toward the correct reading when the barometer is subjected to a large and rapid change in pressure.

Same as constant-level balloon.

A rainbow seen in the spray of the ocean. It is optically the same phenomenon as the ordinary rainbow.

Forecasting weather by the use of numerical models, run on high speed computers. Most of the NWP for the National Weather Service is done at the National Centers for Environmental Prediction (NCEP).

The lowest level at which the wind becomes geostrophic in the theory of the Ekman spiral. Also called gradient wind level.

Wind with a speed between 34 and 40 knots (39 and 46 mph); Beaufort scale number 8.

A type of instrument shelter. It is a wooden box painted white with double louvered sides and mounted on a stand four feet above the ground.

The combined processes by which water is transferred from the earth's surface to the atmosphere: evaporation of liquid or solid water plus transpiration from plants.

The humidity transducinu element in a Diamond-Hinman radiosonde. Also called electrolytic strip.

A combination cup anemometer and pressure-plate anemometer, consisting of an array of cups about a vertical axis of rotation, the free rotation of which is restricted by a suitable spring arrangement.

A device which automatically records the water equivalent of snow on a given surface as a function of time. A small sample of a radioactive salt is placed in the ground in a shielded collimator which directs a beam of radioactive particles upwards. A Geig ...

The ceiling classification which is applied when the ceiling height is determined by timing the ascent and disappearance of a ceiling balloon or pilot balloon.

A polariscope consisting of a specially constructed double plate polarizer and a tourmaline plate analyzer. Polarized light passing through the instrument is indicated by the presence of parallel colored fringes, while unpolarized light results in a unifo ...